TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1642 SUBJECT: GRB 021008, optical observations DATE: 02/10/17 08:10:29 GMT FROM: Sylvio Klose at TLS Tautenburg A. J. Castro-Tirado (IAA-CSIC, Granada), S. Klose (TLS, Tautenburg), L. Wisotzki, S. Huferath (AIP, Potsdam), J. Greiner (MPE, Garching), J. M. Castro Ceron (ROA, San Fernando), and J. Gorosabel (IAA-CSIC) report: Following the detection of the very high fluence gamma-ray burst GRB 021008 (GCN 1617, 1625), we have observed the IPN error box given by Hurley et al. (GCN 1629) with the 2.2m telescope at Calar Alto (Spain) on Oct 14.21 UT (3 x 200 sec, I band) and Oct 15.21 UT (5 x 200 sec, R band) at a high airmass, just before the twilight (5.9 and 6.9 days, respectively, after the burst trigger). The combined R-band image goes ~1 mag deeper than the corresponding DSS-2 red image. No optical transient is found down to the DSS-2 limit (R ~ 20). This message can be cited.